TB-4 Bass Kit

[Simon Barden]

Actually there is more risk in using shims than to trim the heel. But it takes a steady hand and calculations need to be done before attempting a heel trim. The problem with shims is that they can create voids in the neck and pressure will raise the fret board along the lower edge of the neck.

I’m afraid that’s urban myth and has no basis in reality. Shims are fine.

[fender3x]

I’m afraid that’s urban myth and has no basis in reality. Shims are fine.

1+ I believe this also falls under Occam's Razor: Don't alter the body or the neck if there's a simpler solution, particularly one that is tried and true.